The present invention relates to a method of production of a semiconductor light emission device and a method of production of a light emission apparatus, more particularly relates to a method of production of a semiconductor light emission device provided with a plurality of multilayers emitting lights having different wavelengths and a light emission apparatus mounting the semiconductor light emission device in a package.
In general, an apparatus for reading (reproducing) information recorded on a compact disc (CD), digital versatile disc (DVD), mini disc (MD), or other optical recording medium for optically recording information (hereinafter also referred to as an “optical disc”) or writing (recording) information on them (hereinafter also referred to as an “optical disc apparatus”) includes a built-in optical pickup apparatus.
In the above optical disc apparatuses or optical pickup apparatuses, in general, when the types of the optical discs (optical disc systems) are different, use is made of laser beams having different wavelengths. For example, a laser beam having a wavelength of the 780 nm band is used for the reproduction etc. of a CD, while a laser beam having a wavelength of the 650 nm band is used for the reproduction etc. of a DVD.
With the wavelengths of the laser beams differing according to the types of the optical discs as described above, for example, a compatible optical pickup apparatus enabling the reproduction of a CD in an optical disc apparatus for a DVD has been demanded.
A monolithic two-wavelength laser mounting a laser diode for a CD (emission wavelength: 780 nm) and a laser diode for a DVD (emission wavelength: 650 nm) on a single chip is widely used for constructing a compatible optical pickup apparatus enabling the reproduction of a CD and DVD described above. Greater reduction of the size and reduction of the cost of the chip have been demanded (see for example Japanese Patent Publication (A) No. 2000-244060, Japanese Patent Publication (A) No. 2001-77457, and Japanese Patent Publication (A) No. 2001-244546).
In the above monolithic two-wavelength laser, a first multilayer material emitting light having a first wavelength is formed by crystal growth on a flat substrate, then is etched away at periodic intervals to form stripes of the first multilayer. After this, a second multilayer material emitting light having a second wavelength is formed by crystal growth on the substrate with the relief shapes formed by the stripes of the first multilayer and unnecessary parts are etched away to form stripes of the second multilayer between the stripes of the first multilayer.